The learning of a new mesh generator doesn't seem to be necessary. Igg is quiet gambit like but not as easy. ICEM can create IGG files, and perhaps it's better to learn ICEM and after use Numeca 's Fine.however a use of StarCD reveals that mesh generator are not fully compatible, and for a specific application perhaps it will be necessary to learn IGG.
A wrong point is the fact that IGG doesn't offer the possibility to rename blocks and blocks faces (I'don't find this possibility), and it's not easy in FINE to link blocks faces to boundary conditions, unless you write on a paper...
A try has been made with ICEM in order to import grid, but it wasn't efficient, in fact an error happen during the conversion from IGG 4.0 to IGG 4.1 (in fact product IGG 4.0 meshes).